The signature and information in 1. digital signature are separated, so a method is needed to link the signature and information. In the traditional handwritten signature, the signature and the signed information are a whole.

2. On the method of signature verification, the digital signature adopts an open method to verify the signature, and anyone can check it; Traditional handwritten signature verification is judged by experienced recipients by comparing with reserved signature samples.

3. In digital signature, a copy of a valid signature is also a valid signature; In the traditional handwritten signature, the copy of the signature is invalid.

4. Digital signature has two more functions than handwritten signature: confirming the source of data and ensuring that the data has not been modified or changed during transmission. Therefore, in some aspects, the function of data signature is more similar to the function of integrity detection value.